Can I travel to Denmark with UK refugee travel documents?

It depends on the precise type of travel document. If it is a “convention travel document,” with this cover, the answer is yes.

Section IV of this document (“Fritagelse for krav om visum”) details 26 categories of people who are exempt from the visa requirement in Denmark. They include citizens of a number of visa waiver countries, holders of a residence permit in another Schengen country, passports for some of the many many British nationality types (British citizen, BN(O), BOTC, BOC, BPP and British subject), laissez-passers from certain international organizations, etc. It does include aliens’ passports from a few countries, but not British ones.

Item 19 is: Holders of valid travel documents issued under the convention of 28 July 1951 relating to the status of refugees or the agreement of 15 October 1946 relating to the issue of a travel document to refugees, issued by an EU or Schengen country, if the holder is a lawful resident of the issuing country.

Some other categories you might qualify for depending on your particular circumstances, based on a casual reading, are:

20. Participants in school trips within the EU, if the group is led by a teacher who has been issued a specific form for EU school trips.

21. Stateless and refugees under the age of 21 named in a collective passport.

22. Holders of travel documents issued by an EU or Schengen country pursuant to the 1954 convention relating to the status of stateless persons, who are resident in the issuing country.

Courtesy SkyTeam (my emboldening):

DENMARK

Visa required. The following are exempt from holding a visa:

Passengers with an Alien's passport issued by Estonia or Latvia for a maximum stay of 90 days.

Not applicable when traveling to the Faroe Isl. or Greenland.

The max. stay is granted within 180 days.

Additional information:

Visitors are required to hold proof of sufficient funds to cover their stay (at least USD 30.- or DKK 300.- per day of intended stay) and documents required for their next destination.

Except if statement, written by a sponsor residing permanently in Denmark, is available on arrival. This statement must be signed by sponsor on arrival.

Important:

Visitors not holding return/onward tickets could be refused entry.

Visas for travel to the Faroe Isl. and/or Greenland are required to be endorsed "Valid for the Faroe Islands", "Valid for Greenland" or "Valid for the Faroe Islands and Greenland".

SWITZERLAND

The following are exempt from holding a visa:

Passengers with a Travel Document (Convention of 28 July 1951) issued to refugees by Switzerland.

Passengers with a Travel Document (Convention of 28 July 1951) issued to refugees by another Schengen Member State for a maximum stay of 90 days.

The maximum stay is granted within 180 days.

Passengers with a Travel Document (Convention of 28 July 1951) issued to refugees by Ireland (Rep.), Romania or United Kingdom.

Passengers with an Alien's passport issued by Estonia or Latvia for a maximum stay of 90 days.

Additional information:

All passengers entering Switzerland on a one-way ticket can be questioned about the purpose and conditions of the intended stay. Passengers entering on a one-way ticket not holding sufficient funds to purchase a return/onward ticket or to cover their stay in Switzerland, or unable to provide an address of a guarantor in Switzerland (which will be checked by the immigration authorities), or to justify the purpose of the intended stay will be returned to point of origin by first available flight, at the expense of the carrier which brought them into Switzerland;

Visitors are required to hold proof of sufficient funds to cover their stay and documents required for their next destination.

Geneva airport (GVA) is located in Switzerland. At Geneva airport, it is only possible to enter/leave the Schengen Area via Switzerland. Passengers must therefore hold proper entry documents for Switzerland.

At Basle/Mulhouse/Freiburg (BSL), it is possible to enter or leave the Schengen Area via Switzerland or France. Passengers must hold proper entry documents for the respective country.

Important:

Visitors not holding return/onward ticket could be refused entry.

SPAIN

Visa required. The following are exempt from holding a visa:

Passengers with a Travel Document (Convention of 28 July 1951) issued to refugees by Spain.

Passengers with a with a Travel Document (Convention of 28 July 1951) issued to refugees by Switzerland or another EEA Member State, for a maximum stay of 90 days.

The maximum stay is granted within 180 days.

Passengers with an Alien's passport issued by Estonia or Latvia for a maximum stay of 90 days.

The maximum stay is granted within 180 days.

Additional information:

Visitors traveling as tourist must hold proof of sufficient funds to cover their stay (EUR 62.40, per day of stay with a minimum of EUR 561.60, or equivalent in other freely convertible currency), an invitation letter ("Carta de Invitacion") or a confirmation of hotel accommodation and documents required for their next destination. Important:

Visitors not holding return/onward ticket could be refused entry.